macroalage & phytoplankton - soest€¦ · primary production • the production of organic...
TRANSCRIPT
OCN 201 Biology Lecture 4http://video.conncoll.edu/f/pasiv/lucid/Cyanophora-900.html
Marine Primary Producers
Photo: C. Schvarcz (Steward Lab, UH Manoa)
Macroalage & Phytoplankton
Primary production
• The production of organic compounds from atmospheric or aquatic carbon dioxide, principally through the process of photosynthesis (or chemosynthesis)
• Carried out by autotrophs
• On land primary producers are mostly macroscopic
• In the sea nearly all primary production is due to microscopic phytoplankton
Terrestrial Primary Producers
Macroalgae & SeagrassesLarge Marine Primary Producers
Kelp Forest Locations
Exception: Sargassum, a planktonic macroalga
Macroalgae mostly limited to coastal areas
BUT: most life in the sea is microscopic including the primary producers and consumers
Flagellates & Coccolithophores
Diatoms & Dinoflagellates
Cyanobacteria & Picoeukaryotes
MARINE PHYTOPLANKTON
Thousands
Millions
Hundreds of Millions
How Many in a Liter? How much Production?
0
10
20
30
40
50
60
70
80
90
100
0.2 to 2 µm
2 to 10 µm
>10 µm
Perc
ent o
f Prim
ary
Prod
uctio
n
North Pacific
Together, these tiny phytoplankton produce half the oxygen on the planet!
• Prochlorococcus
• Synechococcus
Prokaryotic Phytoplankton (Cyanobacteria)
Responsible for a lot of the primary productivity in the open ocean
(and others)
Eukaryotic Phytoplankton have Plastids that originated as symbiotic cyanobacteria
plastids
Cyanophora
Image: https://ncma.bigelow.org/tree-of-life/archaeplastida/glaucophyta
This process is called kleptoplasty
Some Eukaryotes Steal Plastids from Others
• Picoeukaryotes
• Diatoms
• Dinoflagellates
• Coccolithophores
Eukaryotic Phytoplankton
PicoeukaryotesOstreococcus - smallest free-living eukaryote
François
Universi Wenche Eikrem and
By eye
Light Microscope
ElectronMicroscope
PicoeukaryotesMicromonas pusilla
Dinoflagellates
Diatom Coccolithophore
picoeukaryote
cyanobacteriumSilica frustule Calcium carbonate plates
Cellulosethecal plates
NaviculaFragilaria
DIATOMS
Chaetocerous
http://bioloc.oce.orst.edu/SherrLab/BESTMG9%20epi%20Chaeto.jpg
Siliceous Sediments
http://www.marinebio.net/marinescience/02ocean/mgbottom.htm
http://www.bhikku.net/archives/03/img/diatoms.JPG
Dinoflagellates
Emiliania huxleyi
http://images.quickblogcast.com/77583-67933/coccobloom.JPGhttp://media-2.web.britannica.com/eb-media/94/74594-004-02A9BBFF.jpg
Summary• Kelp and sea grasses important in nearshore in
nutrient rich areas BUT most primary producers are microscopic
• Photosynthetic bacteria (cyanobacteria) are most abundant primary producers on the planet
• The larger photosynthetic planktonic eukaryotes are also very abundant
• Some important groups: diatoms & coccolithophores have hard shells that create massive (and inspirational) mineral deposits